1. Technical Field
The technology disclosed herein relates to a telescoping lens barrel.
2. Background Information
Imaging devices that produce image data about a subject have rapidly gained popularity in recent years. A lens barrel for adjusting the focal distance is mounted in these imaging devices. Examples of known imaging devices include cameras with an integrated lens and those with an interchangeable lens. A lens barrel is built into an integrated type of camera. A camera with an interchangeable lens has a camera body and a lens barrel that can be mounted to the camera body.
A conventional lens barrel is disclosed in Japanese Laid-Open Patent Application 2003-57522, for example. With this lens barrel, the focal distance can be adjusted by moving a lens group along the optical axis direction by rotating a cam barrel via a gear train linked to the motor. A clutch mechanism is installed for one of the gears in the gear train, and is designed so that torque over a certain level will not be transmitted from the motor to the cam barrel. If an external force that would rotate the cam barrel should be exerted when the lens barrel is dropped, for example, the clutch mechanism prevents damage to the gear train by interrupting excessive torque transmission.